152 COLTTBEID^. 



Prontal once and one third to once and a half as long as broad, 

 nearly as long as or shorter than its distance from the end of the 

 snout, as long as or longer than the parietals ; an azygous shield 

 separates the prsefrontals ; eye usually encircled by three to five 

 shields, in addition to the supraocular ; temporals 1 + 2 ; seven 

 upper labials, third or fourth rarely entering the eye ; four or five 

 lower labials in contact with the anterior chin-shields ; posterior 

 ehin-shields small. Scales in 21 rows. Ventrals 131-147 ; anal 

 divided ; subcaudals 29-44. Yellowish or pale brown above, with 

 three series of large black or brown black-edged spots ; three black 

 A-shaped bands on the head and a larger one on the nape ; lower 

 parts black and yellow (red ?), the two colours in nearly equal 



proportion. 



Total length 560 millim. ; tail 80. 



Southern Brazil, Paraguay, Uruguay, Argentina, Southern 



ChUi. 



a-c. d (V. 136 ; 0. 40), Rio Grande do Sul. Dr. H. v. Ihering [CI. 



$ (.V. 181 ; 0. 29), & 



yg. (V. 145 ; C. 40). 



<;?. c3' (V. 134; 0.41). San Lorenzo, Eio Dr. H. v. Ihering [C.]. 



Grande do Sul. 



e-g- 6 (V. 143 ; 0. 44) Dept. of Soriano, E. Havers, Esq. [P.]. 



& yg. (V. 136, 145 ; 0. Uruguay. 



35, 40). 



h-i. cJ (V. 141; 0. 43) Montevideo 



& 2 (V. 132 ; C. 33). 



k. 5 (V. 135 ; 0. 33). Buenos Ayres. G. Wilkes, Esq. [P.]. 



/. 2 (V. 138; 0.36). Buenos Ayres. 



TO-». cJ (V. 147 ; 0. 39) Argentina. Mr. Wilson [0.1. 



& ? (V. 135 ; 0. 36). 



u. 2 (.V. 133 ; 0. 34). S. Ohili. A. Lane, Esq. [0.] ; 



p. Skull. Argentina. 



H. B. James, Ksq. [P.]. 



^ 2. Lystrophis histricus. 



Heterodon histricus, Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 224, 

 and Icon. G6n. 11, pi. iv. fig. 2 (1866) ; Steindachn. Verh. zool.- 

 bot. Ges. Wien, 1864, p. 232, pi. vi. 



nattereri, Steindachn. Novara, Rept. p. 90 (1867). 



Erontal as long as broad, shorter than its distance from the end 

 of the snout, as long as the parietals ; no azygous shield separating 

 the prsefrontals ; one (or two) prse- and two (or one) postoculars ; 

 temporals 14-2; seven upper labials, third and fourth entering the 

 eye ; five lower labials in contact with the anterior chin-shields ; 

 posterior chin-shields small. Scales in 19 rows. Ventrals 133-144 ; 

 anal divided ; subcaudals 27-37. Eeddish above, with more or less 

 regular black cross bars edged with yellowish; sides yellowish, 

 spotted with black ; three black A-shaped bands on the head, and a 

 larger one on the nape ; yellowish-white inferiorly, spotted with 

 black. 



